For every box of Sugar Bombs that the player character bring him, he offers to pay 15 caps, which can be increased to 30 caps by passing a speech check. The player character can then purchase 1 ultrajet from him (around 70 caps each, depends on your Barter skill) for every 8 boxes of Sugar Bombs turned in.

The first time Murphy offers you a look at his inventory, which includes ultrajet and a handful of other drugs, he will have zero caps. Once you purchase ultrajet from Murphy, you can sell him any items in your own inventory to get some or all of the caps back. However, any items you sell him will automatically disappear from his inventory, so do not sell him anything important.

Aside from directly buying ultrajet from Murphy, his inventory can be found inside of a Hard locked footlocker beside his desk. A player with a sufficiently high Sneak skill can steal the ultrajet from his inventory after Murphy creates it. It should be noted that after giving Murphy Sugar Bombs the ultrajet slowly begins to appear in his inventory, at a rate of one every few seconds rather than all at once (apparently giving him time to synthesize it).

Selling Murphy the spacesuit acquired during the Mothership Zeta add-on will result in him wearing it when you next visit him.

Dropping any sugar bombs on the ground near Murphy will result in him picking them up and not paying for them. They won't be in his inventory, making it impossible to steal them back.

pcps3xbox360 After you speak to Murphy for the first time, giving him any boxes of Sugar Bombs will result in you not getting paid. Leaving the area and then returning will fix this problem. [verified]